1. Field of the Invention
The present invention relates to fractionating/collecting devices for fractionating and collecting a separated sample component in a liquid chromatograph, hereinafter also referred to as LC, performing separation analysis of a solution sample.
2. Description of the Related Art
An effluent from a liquid chromatograph is fractionated and collected, and further analyzed in the liquid chromatograph or other analyzing devices such as a mass spectrograph (MS). There a fractionating/collecting device for collecting onto a sample container such as a microplate is used.
One example of the mass spectrograph for analyzing the effluent from the liquid chromatograph is a Matrix Assisted Laser Desorption/Ionization-Time of Flight Mass Spectrometry (MALDI-TOFMS). In the MALDI-TOFMS, when fractionating and collecting sample components separated in the liquid chromatograph on the MALDI-TOFMS analyzing plate using the fractionating/collecting device, the sample components are collected at a number of sites on a single plate. After the collecting process is completed, the plate is manually moved to the MALDI-TOFMS device for analysis.
As only one or two collecting plates can be used in the conventional fractionating/collecting devices, not many analyzing samples can be prepared at night without any workers present, for example, for such MALDI-TOFMS analysis.
Other analyzing methods for analyzing the effluent from the liquid chromatograph includes an LC for performing separation analysis through multiple stages, which include fractionating and collecting the sample component separated in the LC of the first stage with the fractionating/collecting device, and analyzing the collected sample component in the LC of the second stage after processing. In the analysis of protein, for example, in order to further analyze the protein separated in the LC, a digestive enzyme is manually added to the divided and collected sample component of the protein for decomposing to peptide, the peptide being further separated in another LC for analyzing in the MS, and analysis is carried out on the obtained MS data.
In the two-step separation task in the LC, manual tasks such as adding the digestive enzyme take a long time. Therefore, a liquid handler capable of fractionating/collecting and dispensing is used for automatically carrying out the task. Normally in the liquid handler, its probe moves to a fractionating/collecting position of the LC in the first stage to suck in the collected component, and then moves to an injection port in the LC of the second stage to inject the sucked component. Thus, the space in the probe is large, which is disadvantageous especially when a micro LC, for example, is used on the fractionating/collecting side to handle very small amounts of sample.